Fine grain photographic developer containing morpholine



Patented Apr. 24, 1951 FINE GRAIN PHOTOGRAPHIC DEVELOPER CONTAININGMORPHOLINE George L. Steans, New York, N. Y., assignor to a The FECorporation, New York, N. Y., a corporation of New York No Drawing.Application June 6, 1946, Serial No. 674,939

1 Claim.

My invention relates generally to the art of photography, and inparticular it relates to developers, that is, solutions for developinglatent images on photographic film having a silver tween 8.2 and 9. Ihave found that this pH range and the resultant very fine grain obtainedwith my developer to be due largely to the presence of the mcrpholine inthe solution, and that the halide emulsion thereon, after exposure ofthe 5 grain size is measurably increased when other film to the actionof light. alkaline compounds are used instead.

Most developers, or developing solutions, com- An illustrative exampleof a very fine grain prise a developing agent as metol(paramethyldeveloper compounded in accordance with my aminophenolsulphate), a preservative as sodium invention is as follows:

sulfite, an accelerator as sodium carbonate, and a restrainer aspotassium bromide. Silver halide Metol (paramethylaminophenol solvents,as sodium thiocyanate, are also added Sulphate) 6 in certain instances,for decreasing the size of the sodmm Sumte 80 silver grains. While thesedevelopers are relasodmn} thlocya'r late 1 tively satisfactoryfor'larger film sizes where the -P bromlde Morphohne "cc" 1 enlargementfactor is relatively small, I have dis covered that they can be verymuch improved not only for use with films of smaller size, as 35 mm.,but also for the larger film sizes, by the substitution in the solutionfor the alkalies now used of an alkaline compound containing a secondaryamine and an ether group, the compound being known as morpholine of thefollowing formula:

Water to make one liter of solution.

I believe that the foregoing example is the very first disclosure of apractical and highly beneficial metol-containing developing compoundusing morpholine itself. The morpholine aids in maintaining thealkalinity of the solution, and has a very noticeable effect on thekeeping properties thereof when used in concentrations described,

OH CHz 0 NH for it permits the use and re-use of the developer over amuch longer period of time than heretofore 2 2 possible with standard orordinary developers Among the objects of my invention, therefore, arethe formation of an extremely fine grain developer for silver halideemulsion films which has longer keeping qualities than previously knowndevelopers and which maintains its alkalinity over a longer period-oftime than heretofore possible, by means of the addition to the solutionof morpholine. Other objects of my invention will be obvious from thefollowing description of an illustrative embodiment, and still otherswill be specifically pointed out in the following description.

Developers including those containing metolhydroquinone are alreadyknown in the art which use derivatives of morpholine, or which usereaction products of morpholine and sulphur dioxide, and which usesulfites of morphcline, but none of these have the properties of my newand improved developer, and none of these prior diswhich do not containmorpholine.

I have found, further, that morpholine may advantageously be added tothe metol-containing developing solution as above described inconcentrations of between .15 cc. to 3 cc. per liter, which correspondsto 315% to 3% by volume, the resultant solution achieving and retainingall the benefits above described. As used herein, and in the claimappended hereto, the term metol refers to the product commercially andcommonly known as p-aramethylaminophenol sul phate.

Having described my invention, what I claim and desire to secure byLetters Patent is:

A photographic developer essentially consisting of an aqueous solutionof the following ingredients in approximately the amounts indicated perliter of solution:

closures evidence any appreciation of the benefits Paramethylaminophenolsulphate grams 6 attendant the use of morpholine in the developsodium slfite do 8O SOIU-tiOIIJ Sodium thiocyanate do 1 r This particularcompound, morpholine, has otassium bromide do .7 some developingproperties of its own, and. when M honn cc. 1 used as an alkaline agentin connection with metol-containing developing compounds, con- GEORGE L.STEANS. taining preservatives, silver halide solvents and restrainers,my compound has a final pH of be- (References on following page)REFERENCES CITED UNITED STATES PATENTS Number FOREIGN PATENTS CountryDate Great Britain June 27, 1935 OTHER REFERENCES Number Name DateMonthly Abstract Bulletin, published by Peterson Apr. 9, 1940 EastmanKodak 00., Rochester, New York, vol. Wood Apr. 16, 1940 26 (1940), page19.

Wood Apr. 16, 1940 Henney: Handbook of Photography, 1939, Schneider eta1 Dec. 1, 1942 10 pages 334, 335 and 337 to 344 cited.

Kinematograph Weekly 270: p. 32, Aug. 31, 1939.

